Robust, Universal, and Reproducible Zwitterionic Hydrogel Medical Coatings Enabled by Cross-Linkable and Graftable Silatrane Chemistry

High Resolution Image Download MS PowerPoint Slide Indwelling medical devices are essential for modern clinical care but often encounter complications due to surface-related issues, including high friction, poor biocompatibility, biofouling, and coating delamination. Hydrogels, known for their good lubricity, biocompatibility, and antifouling properties, have emerged as promising surface coatings. However, their clinical application is limited by weak adhesion and poor stability, especially under physiological conditions. In addition, current silane-based prepolymer coating solutions for hydrogel coatings suffer from poor reproducibility, reduced coating efficiency, and limited shelf life due to rapid hydrolysis, which generates reactive silanol groups prematurely. To overcome these challenges, this study introduces p(MAST-co-MPC), hydrogel coatings derived from prepolymer solutions containing a copolymer of methacrylate silatrane (MAST) and 2-methacryloyloxyethyl phosphorylcholine (MPC). MAST is a recently synthesized silatrane-based monomer featuring a stable cage-like structure that enables strong covalent bonding to oxide surfaces, along with a methacrylate group that facilitates polymerization and cross-linking. MPC, a zwitterionic monomer, imparts excellent antifouling and lubricating properties to the hydrogel. The resulting p(MAST-co-MPC) hydrogel coatings form robust films on various medically relevant substrates, including silicone, stainless steel, silicon oxide, polyurethane, polystyrene, aluminum, and nickel–titanium alloy. A similar hydrogel prepolymer solution of MPC and 3-(trimethoxysilyl) propyl methacrylate (TMSPMA)─a commercial cross-linking agent─was used as a control to evaluate the structural advantages of silatranes over conventional silanes, where the p(MAST-co-MPC) coating solutions exhibited excellent reproducibility and shelf stability. Furthermore, the p(MAST-co-MPC) hydrogel was applied to medical-grade silicone tubing and evaluated via in vitro blood loop tests, demonstrating a significant reduction in clot formation and adhesion. This study highlights the potential of silatrane-based zwitterionic hydrogels as a broadly applicable and durable surface engineering platform for next-generation implantable and wearable medical devices.